Electrical heating appliance



Ja'n. 15, 1929. l 1,699,405

A. PFAU, J R

E LECTRI CAL HEATING APPLIANCE Filed July 24, 1926l Patented Jan. 15', 1929.

UNITED STATES PATENT OFFICE.

ARNOLD :PFATL JR., or sAN rRANcIsco,

CALIFORNIA, ASSIGNOR TO GLOBAR COR- PORATION. OF'NIAGARA FALLS, NEV YORK, A CORPORATION OF NEW YORK.

ELECTRICAL HEATING APPLIANCE.

Application led July 24, 1926. Serial No. 124,701.

This invention relates in general to electrical heating appliances, and it has more particular relation to electrical heating appliances of the radiant reflector type. l

It is an object of the present invention to provide an electrical heating appliance, and more particularly a radiant reiiector heater, of improved character and design which is of simple and inexpensive construct-ion and extremely durable and efficient in operation.

It is a further object of the present invention to provide a radiant reflector heater of improved design and construction embodying reflector and housing elements of such design and so disposed relative to the heating element as to insure facility of assembly of parts and the production of desirable heating effects in operation, through both radiation and convection, and a desirable degree of insurance against overheating of surrounding objects.

it is a further object of the `present invention to provide an improved form of electrical heating appliance ofthe character described an embodying a heating unit land an improved form of niounting therefor which facilitates ready removal of the heating element from and its replacement in the appliance, and which contributes to the simplicity of construction and assembiy and the efficient operation and extended useful life of the heating appliance.

These and other objects and advantages are attained bythe present invention, various novel features of which will be apparent from the accoinpanying description and drawings, disclosing an embodiment of the invention, and will be more particularly pointed out'inthe claims.v

in the drawings:

Fig. 1 is a view in front elevation, withV parts broken away, of a heating appliance embodying features of the present invention.

F ig. 2 is a section, in the plane of the line lI-II of Fig. 1. n

Fig. 8 is a view in side elevation of a detail of a slightly modified form of the heating appliance shown in Figs. 1 and 2.1

Li is a plan view of a detail of the apparatus shown in Fig, 3. Y

In accordance with the disclosure of the drawings, a heating appliance includes a pair of spaced side or end frames or pieces 10 which are relatively rigid and self-supporting, being preferably provided withl supporting feet 11 disposed along the lower side thereof adjacent the front and rear edges of the side frames. Each side frame includes a body portion 12 from which the supporting feet 11 project, these supporting feet being of any relative size and spacing desired,-and an upper extension of reduced width tapering upwardly and curving forwardly along any suitable curvature, depending upon the desired curvature of the reflecting element of the heating appliance.

The side frames 10 sired spaced relation by spacing or tying rods or bolts 16, 17, 18, the rod 1G being disposed at the lower forward edge of the frames, the rod 17, at a lower rear edge of the frames, and the rod 18 at the upper forwardly projecting extremity of the upper extension 15 of the frames.

Each of the side frames 10 is provided along its periphery at the inner side thereof with an inwardly extending and substantially continuous flange or bead, indicated at 20 at the forwardly presented edge of the side frame, and at 21 at the rear and lower edges of the side frame.

x A reflector element 23 and a rear or outer enclosing wall therefor 24 are mounted upon and between the two spaced side frames 10. The side edges of the front wall or reflector element 23,-which is preferably of polished sheet metal and of desired curvature of reflecting surface is arranged to lie behind and along the inner face of the front dange or bead 20 associated with the vertical extensions 15 of the side frames and to lie between and be positioned by said flange and a suitable continuous projection or series of projections disposed at the inner faces of the side frames, and indicated at 25 extending substantially to the front edge of the body portion 12 of each side frame, the upper part of this series of projections being indicated as being made up of spacedy projections and the lower part of a substantially continuous flange 25a provided with spaced projections. Spaced forwardly and may be held in de-` body portion 12 of each side frameand in substantial prolongation of the portion of flange on the upper extension 15 is Va continuous ange or series of projections 26, the side vedges ofthe lower cur-ved portion vof the reflector being positioned between the i sheet metal and is held in close association with theinner face of the flange or bead 21 along the rear and bottom edge of the two side frames10, being maintained in position other, as indicated at 28.`

between the flange 21 and a series ofprojections 27 extending parallel to and slightly spaced inwardly from the flange 21 throughout-the length of thelatter. This rear wall 211 is preferably of substantially the same curvature as the front reflecting wall 23, being, however, more widelyy spaced from the latter at intermediate points and with the space between the two walls gradually taper ing inv width toward the upper and lower forward edges, as indicated.

The reflector 23 and the rear wall 24e may be secured together in assembled relation by interlocking a bent or hook-shaped portion at the upper edge of the frontwall 23, with a tubular shaped formation of the upper edge ofthe rear wall 24, the twovwalls together at this point forming a substantially closed tube, with portions of each wall bracing the i rlhe two walls may be` permanently secured together at their upper edges in the shape indicated or they may be releasably interloclred in position. The lower forward and upwardly projecting edge portions of the front and rear walls 23, 24 may be brought and held together, a preferable arrangement being that indicated at 29, wherein the Vforward edge of the wall 24 is rolled baclrrfardly to form a tubular'portion with a forwardly ei;- tending edge which fits into al rearwardly turned'hool formed in the forward edge of the reflector element v23. The parts 23and 24 may be permanently or releasably secured together theirforward edges in the positions indicated. rlhe space within the interlocked upper edges of the parts and 2d, indicated at 28, is ladapted to receive the securing rod 18, and the space within vthe interloclred forward vedges of these parts adapted to receivethe securing rod 16.

The side frames 10 may be held in desired s iaceda )art relation b nuts or oro'ec'tions von the rods 16, 17, 18, against the inner 'face of th side frames, the terminal cap nut-s 19 on such rods bearing against the outer side of the side frames and serving to prevent separation of such side frames and the assembled reflector 23 andV rear wall 24,701 the latter members 23 `and 24, through the cooperation of their side edges with the inner faces of the side frames, may be relied upon Vto hold the latter in the desired spaced apart relation when the parts areassembled and secured inV such condition by the securing nuts 19 on the rods 16, 17', 18. The positioning ofthe securing rods 16, 1T, i8 within 'the confines of the walls 23 and 24, as indicated,vserves toeffectively conceal these rods, a feature which contributesto the appearancec-f the assembled heater. y

Mounted at the inner side of the body portion 12 of each of the side frames 10 is a bloclr of insulating material 32, lield inposition en a seat between a pair of spaced positioning flanges or ribs 34, by one or more screws or bolts passing through the body portion of the fra-me, the adjacent edge portions of the refiector 23 being slotted to any required extent topermit-,easy passage of this insulatingblocli 32 and the contactsand terminal connections associated therewith. A contact element 36 is mountedv upon the insulating block 311 at the inner side thereof', being secured in position by one or more screws or bolts 37. This contact element 36 is shown as extending upwardly from4 the support 3A andlha'ving itsy upperend slightly bowed or offset awayV from the support, as indicated; and the Contact element is of resilient conduct-ive material, preferably suitably resistant to hightemperatures, such as steel or an iron-chromium or ironchrcmium nickel-alloy, such as ascoloy. This resilient portion of the Contact element has mounted thereon a contact strip 38 of relatively softer and more highly conductive material, such as aluminum or an aluminum-nickel alloy, such as alumel. The terminal portions of each Contact element 36 and contact strip 38, or at leasteach contact strip, is provided with a shallow contact recess, indicated at 39. ifi sel-sustaining` heating element l-l, preferably in the forni of a molded and heathardened compo... on product containine;- siliconv carbide and having its terminal portions of increased conductivity, is disposed between the cont-act terminals with the ends of the heating element in buttfend engagement with the walls ofthe recessed contact portion 39. lilith the heating element 4l disposed in such butt-end engagement with the contact portions of the contact elements 36, and the latter of suitable and desired yielding resilient'character, and biasec toward each-other, the contact elements engage the terminal ends of the heat-- ing element with' sufficient for e to efficiently maintain the heating element mechanically supported in desired operative positicn and toinsure` desirable and efficient electrical engagement between the contacts and the terminals of the heating element.

The contact elements are preferably so mounted that the contact portions thereof and, consequent-ly, the heating' element sup-V ported therebetween, are disposed substantially at the focus of the curve of at least. the major portion of the exposed or active reflecting' wall 23, thus insuring reflection of heat rays emanatingl from the heating element in the desired direction or directions, that is, to form a parallel beam in the case of a parabolic reflector, a divergent beam in the case of a hyperbolic reflector, and convergent beam in the case of an elliptical reflector.

The preferable arrangement as to the shape of the reflector wall 23 is along a single curvature, parabolic, hyperbolic, or elliptical, about a focus substantially coincident with the longitudinal axis of the heating element, to a point substantially beneath the heating element; and fromV this latter point, the wall of thereflector element is carried forwardly or upwardly as a. plane surface or along any suitable curvature to a point somewhat below the heating element, but to a suflicient height to act as a shield or barrier preventing the direct radiation of the heating element from striking the floor or other support at too short a distance from the heating element. A desirable rangement is one wherein the true curvature of main portion of the reflector wall extends forwardly to the point from which reflected heat rays just clear the upper edge of the barrier or shield formed by the forward and upwardly turned portions of the walls 23 and 24. A considerable portion of the rays striking this forward and upwardly turned portion of the reflector are reflect-ed back on the body portion of reflector and thence reflected forwardly and upwardly into the room.

lith the upwardly projecting forward edge portions of the reflecting wall 23 and the rear wall or housing` 25 terminating at a point below the heating element 4l, as inf dicated, the latter is exposed in its full brilliancy to View from the front of the heater; and this latter feature, combined with the fact that avery large portion of the reflector element is exposed to view from the sides, for the reason that the upwardly extending portions l5 of the side frames do not afford any concealment of the reflector, causes the heater when in operation to present a very pleasing effect upon the eye.

The rear wall 25 is apertured at a corvenient intermediate point adjacentl the points -of support of the insulating .blocks 32, as indicated at 45, the aperture being preferably provided with a tubular insulator, flexible insulating conductors 46 passing through the aperture 45 and through the space between the reflecting wall 23 and the rear wall 24, whence they pass through the slots in the edges of the reflector member and are connected to the contact elements 36 by means ofthe securing screws 37. However, the flexible insulated conductors 4G may be connected to Contact elements of an insulating plug or connector having one part -thereof suitably mounted in the rear wall,

24 or the body portion of one of the side frames l0, current being furnished to the appliance through a flexible connection having a terminal plug adapted for cooperative association with such terminal Contact elements fixed in the rear wall or the side frame.

A relatively stiff protective grille or open frame 4S may be provided as a desirable form of protection for the heating element 42 and its live contacts 3S, thus insuring against accidental breakage of the heating element or accidents due to contact with live or heated parts of the apparatus. This grille or frame 48- is preferably bent or curved to a shape corresponding to the cooperative upper edges of the body portion l2 of the side frames. The lower or forward edge of the grille 48 is intended to rest on the rolled over lower or forward edge portion, at 29, of the rear wall 24; and the side frames l0 are provided on their inner faces, preferably beneath the flange 20, slotted projections 5l, projecting trunnion portions 52 on the rear edge of the grille being removably disposed within the recesses of the raised portions 5l.v The trunnion portion 52 on the rear edge of the grille may be readily inserted beneath the flanges 20 on the side frames l0 and into the slots of the portion 5l, and when these portions are so disposed, the grille may be swung fronr normal posit-ion, indicated in the drawings, about the trunnions 52 as a. pivot to such position as will readily permit the removal and replacement of the heating element 41. Because of the fact that the upper part of the grille is approximately horizontal, it may-readily serve as a support for a utensil or article t-o be heated.

uring operation, the reflector wall or member may become quite hot; but due to the provision of the air space between the reflector wall 23 and the rear wall or housing 24, the latter doesnot become heated to such an extent as to be a source of danger to articles in Contact with or adjacent this rear' wall 24. The air space between the -two walls may be in the form of a substantially dead air space or, preferably, it may be provided with suitable apertures at the bottorn toward the front, as indicated at 56, formed in the rear housing 24, and,`if de# sired, at the top along the upper forwardly projecting edge of this rear wall, as indicated at 57, or of the reflector member 23, or both elements 23 and 24. This arrangewith Cil

ment permits and provides for the circulationL of cool air entering, through the apertures 56, the chamber between the two walls 23, 2d, this air. passing upwardly between the walls and becoming heated through contact Awith the reflector wall 23 and passing upwardly and outwardly, through the apertures 57, in one or both of the )arts 23, 2e,

A in the form of a current of warm air which spectively, as desired.

spreads throughout the room.

If desired, the reflecting wall 23 mayV also be provided with one or more openings 5S near the lowest portion of the element, that is, beneath the heating element el, which will serve to admit air from the space betweennthe walls 23, 24 and provide for the upward circulation of'Y a `current of air which becomes heated through Contact with the heating element Lil and thc front face of the reflector 23. Y

- DependinT upon the space to be heated by the heating appliance, the reflecting wall 23 and the corresponding supporting portions of the end frames lO-may be of any desired shape, and, by varying the relative heights of the front and rear supporting feet l1, the body portion of the reflectingelement maybe tilted forward or backward to-project the heat radiated fromthe reflector more nearly downwardly or upwardly, re- A handle to facilitate portability may be attached to the rear wall 2e adjacent its upper edge.

ln order that the inner face of the body portion l2 of the sioe frames l() may gresent a finished appearance,` polished plates 6l of material similar to the reflector element 23 maybe secured in position so as to cover all otherwise exposed inner portions of' the side frames, these plates 6l being recessed to fit around the insulating blocks 32 and being secured in place on raised portions `or seats 62 formedon the side frames, by means of screws 63 passing' through the plates and threaded into the raised seats 62.

ln the modification shown in Figs. 3 and 4t, two heating elements fila, lib, with corresponding contact elements 36a and 36h, are disclosed. rlwo contact elements 36u and Y 36'jr are mounted on aninsulating block 32a lheld in oosition on a seat on each side frame l0, being secured between positioning Vribs 34:,as generally indicated in Figs. l and 2. As indicated, the circuit is from one side of the supply line, through a contact element- 36, heating element ll, contact element 3ba on the other side frame, bridging element 71, connecting the latter Contact element 36 Vto the adjacent contact element 36D, and from the latter through heating element alb and contact element 36" on the first side frame, to the other side of the supply line. The contact' elementsfofthe heater of Figs. 3 and e are-preferably so positioned that the heathereinabove described provides a ing elements all, all are symmetrically grouped about a focus ot' the'main or portion of the reflector element 23.

lt will be apparent that the invention very simple design which permits or Afacilitates ready and inenl ve manufacture and sembly, and lil/rey e presents a very sturdy and pleasing appearance. Further, the de*- sign of the supporting and reflecting elements of the heater body and of the contact elements which, of themselves, insure satisfactory mechanical and electrical mounting of the heating element, provide for ready removal or replacement of heating elements and generally contribute to prolongation of the useful life of a heating appliance.

l should be understood that it is notdesired that the invention claimed be limited lto the enact details of design and construction shown and described herein, for obvious changes will be apparent to persons skilled in the art to which this invention relates.

lt is claimed and desired to secure `by Letters Patent:

l. in an electrical heating appliance,.the combination of a reflecting member supported in operative position, an electricalV resistance heating element mounted in front of a portion of said reflecting.membeig-and a continually upwardly extendingwall curvforwardiy at its upper portion supported in the rear of said reflecting member and spaced therefrom, said reflecting memberl having a. portion extending upwardly at its lower side in front of the body portion of said reflecting member and located forwardly of said heating element, said upwardly extending portion being so formed and disposed relative to said heating element that heat radiated from said heating element isreiiected by said upwardly extending 4portion upon the body portion of said reflect.- ing member.

2, ln an electrical heat-ing appliance, the combination of a reflecting member supported inY operative position, an electrical resistance heating element mounted in front of a portion of said reflecting member, and a wall supported in the rear of said reflecting member and spaced therefrom, said reflecting member and said wall having portions extending upwardly at their lower side in, front of the body portion of said reflecting member and said rear wall and forwardly of said heating element, the space between said rehecting member and said rear wall' having openings to the surrounding air at points adjacent the upper and lower ends of saic space-:said forwardly and upwardly extending portion ofi said reflecting member being adapted toreflect upon thel body portion of the latter heatk radiated from said heating element..

3. In an electrical heating appliance, the

body

lil

combination of a reflecting member' supported in operative position, an electrical resistance heating element, means for defachably mountingjsaid heating element in front of the body portion of said reflecting member, and a wall supported in the rear of said reflecting member and spaced 'therefrom, said reflecting member and said wall having portions at their lower side spaced from each other and extending upwardly in front of the body portion of said reflecting member and said rear wall, said upwardly extending' portion being adapted to reflect upon the body portion of said refiecting member heat radiated from said heating element, and the upper edge of the upwardly extending` portion of one of said parts having a portion rolled over the upper edge of the corresponding portion of said other part.

a. In an electrical heating appliance, the combination of spaced and rigid supporting side frames, a reflecting member ldisposed in operative position between said side frames, an electrical resistance heating element, means for mounting said heating element in front of a portion of said reflecting member, a wall disposed in the rear of said reflecting element and spaced therefrom, and means associated with said side frames for mounting said reflecting member and'said rear wall in operative position with parts thereof cooperative with said side frames, said side frames and said reflecting member and rear wall serving to form an air space open adjacent its lower and upper ends and extending continuously upward.

In an electrical heating appliance, the combination of spaced and rigid side frames, a heating element, means carried by said side frames for mounting said heating element in operative position,` a reflecting member disposed in operative position between said side frames, a wall disposed in the rear of said reflecting member, said side frames having Vpor yions thereof cooperative with edge portions of said reflecting member and said rear wall to definitely position the latter, and means associated with said side frames for securing said reflecting member and said rear wall in operative position relative to said side frames and said heating element.

6. In an electrical radiant heater, the combination of spaced supporting side frames, a reflecting` member disposed in operative position between said side frames, an electrical resistance heating element, means carried by said side frames for detachably mounting said heating element in front of a portion of said reflect-ing member, andy means associated with said side frames for detachably securing said reflecting member in operative position between said side frames.

7. In an electric radiant heater, the combination of a pair of spaced supporting side frames, a reflecting member, a heating element mounted in operative position relative to said reflecting member, a wall disposed in the rear of said reflecting member and spaced therefrom, said reflecting member and said wall having portions at their lower side. extending upwardly'to an appreciable extent, said upwardly extending portion of said reflecting member being positioned to reflect upon the body portion of said reflecting member heat radiated from said heating element, and means carried by said side frames for securing said reflecting member and said rear wall in spaced operative relation.

8. In an electric radiant heater, the combination of a. pair of rigid supporting side frames, a reflecting member, a wall supported in the rear of said reflecting member and spaced therefrom, said reflecting member and said wall having portions at their lower side extending upwardly to an appreciable extent, said upwardly extending portion of said reflecting member being positioned to reflect upon the body portion of said reflecting member heat radiated from said heating element, said side frames being provided with projections at the inner faces thereof, and said reflecting member and said rear wall having their edge portions cooperative with said projections on said side frames, and means for holding said reflecting member and said rear wall in operative position with their side edges associated with said projections on said side frames.

9. In an electric radiant heater, the combination of a pair of spaced supporting side frames each having a body portion and a reduced and continuously upwardly curved extension therefrom, a reflecting member disposed in operative position between said side frames, said side frames having their forward edges provided with inwardly projecting flanges, and means carried by said side frames for supporting said reflecting member in operative position with portions of its side edges in engagement with said side frames beneath said flanges with a substantial part of the inner surface of said side frames exposed forwardly and upwardly of the lower portion of said reflecting member.

l0. In an electric radiant heater, the combination of a pair of spaced and rigid supporting side frames eachy comprising a body portion and a relatively narrow upper extension therefrom, said extension being provided with inwardly projecting flanges at its forward and rear edges, a reflecting member disposed between said side frames, a wall disposed at the rear side of said reflecting member and spaced therefrom, and means for supporting said reflecting member and said rear wall in spaced operative reliz said side frames and with said parts constituting an upwardly extending and continuously curved air space of gradually deci-casino' area'toward its o )en end.

ll. In' an electric radiantheater, the cour.

bination of a'pair of spaced and rigid supporting sidel'rames each comprising a body portion and a relatively narrow upper extension therefrom, said extension being provided with inwardly projecting flanges at its forward and rearedges, a reflecting member, a wall disposed at the rear side of said reflecting member' and spaced therefrom, and means for supporting said reflecting member and said rear wall in spaced and operative relation with the side edges of portions of said reflecting member and said rear wall held within said inwardly projecting flanges on said side walls, terminals mounted on the body portions of lsaid side framesat the inner `face thereof, 'said terminals comprising yielding and resilient Contact portions biased toward each other, and a self-sustaining electrical resistance heating ,element yieldably and detachably maintained in electrically and mechanically operative position by and between said terminals, f

l2. In an electric radiant heater, the combination'ota pair of spaced supporting side frames, said side frames being provided with inwardly extending Vflanges at thel forward edge of the' upper portions of' said side frames, a reflecting member mounted in operative position between said side frames with its side edges held in position beneath said flanges, an electrical resistance heating' element disposed in operative position forwardly of said reflecting member. and means for mounting said heating` element in operative position comprising` terminals carried by and insulated from portions of said side frames below said inwardly projecting ilanges.

.13. In an electric radiant heater, the combmation of a pair of spaced supporting side frames each comprising a body portion and a reduced upwardly projecting extension therefrom, a reflecting member', means asso.- ciated with said side frames for supporting` said reflecting memberV in operative posi@ tion, an electrical Vresistance heating element mounted in operative position in front of saidreflecting member, said reflecting member having a portion extending upwardly at its lower side in front of said heating ele'- ment, an open protecting grill movably mounted on the body 'portions of said side fra es and disposed above said heating elcment when in operative position.

' 11i. ln an electric radiant. heater, the combination of a pair of spaced supporting side frames, a reliecting member supported in operative position, a walldisposed at the rear oi said reHec-ting member and spaced therefrom, said reflecting member and said wall having portions at its lowersiderentending forwardly and upwardly to an appreciable extent, an electrical resistance heating element mounted in operative position in front of said reflecting member, means for securing said reflecting member and said rear wall in spaced operative relation, 'said means being cooperative with said sideV frames, and a detachable open grill havingits front edge supported at the upper edge of the forwardly projecting portions of said reflecting member and said rear wall and lying above said heating element as a protector therefor.

l5. ln an electric radiant heater, the combination of a pair of spaced supporting sido frames each having a body portion and a reduced upwardly projecting` extension therefrom, a reflecting member disposed in operative posicion between said side frames adjacent the 'forward edges of said reduced extensions, an electrical resistance heating elementU disposed in operative position in front of the lower portion'of said reiiecting member, terminal mounting means carried by the body portions of said side frames for yieldinf'ly supporting said heating element, and meansV lcarried by said side frames for supporting said reflecting member in operative position with respect to said side frames.

16. ln an electrical radiant heater, the combination of spaced supporting side frames, a reflecting member secured in op-` erative position between said. side frames, an elongated, self-sustaining resistance heating element disposed in position in front of said reflecting member and extending transversely of the planes of said side fra Jes, and Contact elements at least one of which includes a resilient portionmounted on said side frames andV adapted to detachably and resiliently mount said heating element in mechanically and electrically operative position through pressure exerted in the direction of the longitudinal axis of said hea-ting element. v

ln witness whereof I aflix my signature hereto.

ARNOLD Prati, JR. 

